Artificial silk.



UNITED STATES PATENT OFFICE.

HARRY S. MORK, OF BOSTON, ARTHUR D. LITTLE, OF BROOKLINE, AND WILLIAM H.WALKER, OF NEWTON, MASSACHUSETTS, ASSIGNORS, BY MESNE ASSIGNMENTS, TOCHEMICAL PRODUCTS COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OFMAINE.

ARTlFlCIAL SILK.

SPECIFICATION forming part of Letters Patent No. 712,200, dated October28, 1902.

Application filed January 13, 1902. Serial No. 89,532.

T0 on whom it may concern:

Be it known that we, HARRY S. MORK, of Boston, county of Sufiolk, ARTHURD. LIT- TLE, of Brookline, county of Norfolk, and WILLIAM H. WALKER, ofNewton, county of Middlesex, State of Massachusetts, have invented anImprovement in Artificial Silk, of which the following description, inconnection with the accompanying drawings, is a specification, likeletters on the drawings representing like parts.

Our invention relates to artificial silk, and especially to artificialsilk which is waterproof, and thereby different from and superior to theartificial silk heretofore produced, from which, moreover, our productdiffers in other essential particulars, as hereinafter set forth.

Without exception,so far as known to us,all commercial artificial silksthus far produced consist, essentially, of cellulose more or lessmodified or degraded by the cycle of chemical treatments to which it hasnecessarily been subjected in the processes of their manufacture. Theproperties of these artificial silks, and especially their relations towater, are thereafter, substantially, those of cellulose in its modifiedor degraded forms. Especially is the strength of all products of theprior art greatly influenced by the moisture they contain. They allabsorb water readily and are greatly weakened by being wet.

As a step in the production of cellulose artificial silk from celluloseby certain processes artificial filaments of nitrocellulose are nowprepared commercially in considerable quantities. These filaments andthe threads produced therefrom are, however, extremely inflammable andunder appropriate conditions explosive, for which reasons they are ut-.terly unfitted for use in textiles and are not so employed. For theproduction therefrom of a merchantable material these nitrocellulosefilaments or threads are thereforealways subjected to further chemicaltreatment by which the nitrocellulose forming their substance is reducedto cellulose, which is the material of (No specimens.)

which the finished product consists. During this treatment not only dothe filaments lose a considerable proportion of their weight, but thetreatment itself is expensive.

We have discovered that artificial silk can be produced by propermethods from certain stable non-explosive and relatively non-inflammablecompounds or of derivatives of cellulose, and notably from the simple ormixed cellulose esters of the fatty acids, and of these compounds weprefer cellulose acetates, and particularly the compound known ascellulose tetracetate. We have discovered that these compounds, andespecially the compound specified, yield either by themselves or withsuitable additions, as hereinafter indicated, filaments of sufficienttenuity .and strength to permit of their use as artificial silk, forwhich use, moreover, they are preminently qualified by the greatbrilliancy of their luster and the fact that they are waterproof. Thesefilaments, moreover, may readily be produced or dyed in any color.

The physical properties of our new filaments and threads-such as theirsoftness,

strength, and elasticitymay be modified or made to vary over aconsiderable range by incorporating with the cellulose ester or othercompounds mentioned various softeners, as oleic acid, acetylatedcastor-oil, thymol, phenol, c.

Our new product has the important and unique ad vantage over all otherartificial silks heretofore known of being entirely unaffected by water,and the chemical nature of our filaments is such as to permit at once oftheir commercial use. The radicals in combination with the cellulosemolecule in our filaments as first formed constitute an essential andintegral part of our commercial product.

We have set forth in another application, Serial'No. 125,738, methodswhich we have found convenient for the manufacture of our product; butthe methods themselves form fatty acids in combination with a softener,as oleic acid, acetylated castor-oil, thymol, phenol, &c.

What we do claim, and desire to secure by Letters Patent, is-

1. As a new article of manufacture artificial silk composed of a stable,non-explosive compound of or derivative of cellulose.

2. As a new article of manufacture artificial silk composed essentiallyof the cellulose ester of an organic acid 3. As a new article ofmanufacture artificial silk composed essentially of the cellulose esterof a fatty acid.

4. As a new article of manufacture artificial silk composed essentiallyof cellulose acetate.

5. As a new article of manufacture artificial silk composed of a stable,non-explosive cellulose compound, modified by the addition of a softeneras above described.

6. As a new article of manufacture artificial silk composed of thecellulose ester of an organic acid, modified by the addition of asoftener as above described.

7. As a new article of manufacture artificial silk composed of thecellulose ester of a fatty acid, modified by the addition of a softeneras above described.

8. As a new article of manufacture artificial silk composed of celluloseacetate, modified by the addition of a softener as above described.

In testimony whereof we have signed our names to this specification inthe presence of 35 two subscribing witnesses.

HARRY S. MORK. ARTHUR D. LITTLE. WILLIAM H. WALKER. Witnesses:

B. J. NoYns, M. E. BILL.

